Preterite stem changes: o to u
In the preterite tense, a small group of -ir verbs undergo a stem change where the o changes to a u.
Just like the e → i change, this shift only happens in the third-person forms: él/ella/usted and ellos/ellas/ustedes. The other forms keep the regular o in the stem. The two most common verbs that follow this pattern are dormir (to sleep) and morir (to die).
| Pronoun | dormir | morir |
|---|---|---|
| yo | dormí | morí |
| tú | dormiste | moriste |
| él/ella/usted | durmió | murió |
| nosotros/nosotras | dormimos | morimos |
| vosotros/vosotras | dormisteis | moristeis |
| ellos/ellas/ustedes | durmieron | murieron |
You might use these verbs when telling stories about a pet (la mascota) or the vet (el veterinario).
| The vet came, but the pet died. | La veterinaria vino, pero la mascota murió. |
| The birds died and the boy cried. | Los pájaros murieron y el niño lloró. |
Talking about sleep habits
When talking about resting, you can pair dormir with adverbs like profundamente (deeply) or use it in the phrase dormir la siesta (to take a nap).
| The boy slept deeply last night. | El niño durmió profundamente anoche. |
| The women slept here and snored. | Las mujeres durmieron aquí y roncaron. |
You can also combine these forms with regular verbs related to sleep routines, such as roncar (to snore), soñar (to dream), and despertar (to wake up). Keep an eye out for nouns like el sueño, which can mean both "the dream" and "sleep" in general.
| The girl took a nap, dreamed and woke up happy. | La chica durmió la siesta, soñó y se despertó contenta. |
| He woke up nervous because the dream was bad. | Él se despertó nervioso porque el sueño fue malo. |
